rsvg_internals/build.rs: Fix native, non-cross Windows builds
Hi,
A recent change in rsvg_internals/build.rs broke native builds on Windows as it included a system Rust module that is supported on *nix only, std::os::unix::fs::symlink.
From the commit message:
Commit e310e36b broke builds on native Windows as it assumed the build is running on *NIX and is cross-compiling for Windows. Fix this by:
Including the *nix-only items conditionally, and include the Windows symlink items only on non-MSVC builds. The MSVC build files handle how the rust-built rsvg-internals.lib is being linked, so we don't need to build nor use generate_convenience_lib() on MSVC builds.
Only include the items related to generate_convenience_lib() when it is indeed being built.
At this point we do not support cross-compiling on *nix for MSVC builds, and it is unlikely it would be supported, at least in the near future.
With blessings, thank you!